This invention relates generally to an electrophotographic printing machine, and more particularly concerns a cleaning apparatus employed therein.
In the process of electrophotographic printing, a photoconductive member is charged to sensitize the surface thereof. A light image of an original document is projected onto the charged photoconductive member selectively dissipating the charge thereon. This records a latent image of the original document on the photoconductive member. Heat settable particles, i.e., toner particles, are generally employed to develop the latent image. These particles are deposited on the photoconductive member and subsequently transferred therefrom to a sheet of support material. Heat is then applied to the toner particles to permanently affix them to the sheet of support material forming a copy of the original document.
Invariably, some residual toner particles remain adhering to the photoconductive surface after the transfer of the toner particles to the sheet of support material. These particles must be removed from the photoconductive surface prior to the initiation of the next successive cycle. This may be achieved by a cleaning web engaging the photoconductive surface to remove the residual toner particles therefrom. The unused cleaning web, stored on a supply spool, is advanced therefrom and maintained in engagement with the photoconductive surface by a pressure roller. A take up spool stores the unused or dirty cleaning web remote from the photoconductive surface. Hereinbefore, if the cleaning web slackened and folds developed therein, rotation of the pressure roller would cause the cleaning web to be entrained erroneously thereabout. This will jam the operation of the electrophotographic printing machine requiring correction of the problem by an operator prior to the resumation of copying.
Accordingly, it is a primary object of the present invention to improve the cleaning system employed in an electrophotographic printing machine by preventing the cleaning web from being entrained about the pressure roller.